Pratt truss

The Pratt truss is named after Thomas and Caleb Pratt, Boston railroad engineers who patented the design in 1844. The Pratt and its variations are the most common design of metal truss bridges.
On a basic Pratt truss, the diagonals slope toward the center of the bridge, do not cross any verticals, and are approximately parallel. The top chord is straight and parallels the lower chord. The panels can have sub-divisions - or verticals and diagonals that don't reach from the top to bottom chord, though this can be considered a variation of the basic type.
There are many variations, or sub-types of the Pratt truss, some of which have their own name including Parker, camelback, Pennsylvania, Baltimore, and others.
It is used in bridges as a through truss, pony truss, and deck truss.

CN - Thornapple River Bridge (Rusk County, Wisconsin)Built 1907, Rehabilitated Ca. 2006Pratt through truss bridge over Thornapple River on Canadian National RailwayOpen to traffic

CN - Trempeleau River Bridge (Trempealeau County, Wisconsin)Pratt pony truss bridge over Trempeleau River on Candian National RailwayOpen to traffic

CN - Yellow Creek Bridge (Stephenson County, Illinois)Built 1904Through truss bridge over Yellow Creek on Canadian National RailwayOpen to traffic

CNJ - Lehigh River Bridge (Lehigh County, Pennsylvania)Built ?; One span lost to flooding 1902.Abandoned pratt through truss bridge over Lehigh River on Central Railroad of New JerseyAbandoned

CNJ - South Branch Raritan River Bridge (Somerset County, New Jersey)Built 1896,Abandoned pratt through truss bridge over South Branch Raritan River on Central Railroad of New JerseyDerelict/abandoned

CNJ/LV Overpass (Old) (Carbon County, Pennsylvania)Built 1888; Replaced 1906Lost Pratt through truss bridge over Lehigh Valley Railroad on Central Railroad of New JerseyReplaced by a new bridge

CNTP - New River Viaduct (3rd) (Scott County, Tennessee)Built 1908; Replaced by a new bridge and mostly removed 1963Abandoned Pratt deck truss bridge over New River once carried Cincinnati, New Orleans and Texas Pacific Railway's Cincinnati Southern Railroad (later Norfolk Southern), before being bypassedAbandoned

CNW - Clinton Bridge (East Channel) (Whiteside County, Illinois)(Main design: Other through truss)Built 1865; Reconstructed 1868 & 1874; replaced by a new bridge in 1908McCallum through truss bridge over Cat Tail Slough on RailroadReplaced by a new bridge

CNW - Clinton Bridge (West Channel) (Clinton County, Iowa)(Main design: Bollman through truss)Built 1865; Approaches reconstructed 1874; Drawspan replaced 1887; Approaches reconstructed again 1898; replaced by a new bridge in 1908Lost Bollman through truss bridge over Mississippi River on RailroadReplaced by a new bridge

CNW - Deering Swing Bridge (Cook County, Illinois)Built 1887; Replaced 1916Lost Pratt through truss bridge over South Branch Chicago River on Chicago & North Western RailwayReplaced by a new bridge

CNW - Moingona Bridge (Boone County, Iowa)(Main design: Parker through truss)Built 1894, Removed 1933Lost Parker through truss bridge over Des Moines River on Chicago & North Western RailwayRemoved but not replaced

Coal Creek CR 100N Bridge (Fountain County, Indiana)Built 1886 as part of a 7-span bridge in Attica, moved to this location in 1924Pratt through truss bridge over Coal Creek on CR 100 NorthOpen to traffic

Coal Creek CR 230W Bridge (Vermillion County, Indiana)Lost Pratt through truss bridge over Coal Creek on County Road 230 WestReplaced by a culvert

Coaldale Bridge No. 1 (Fremont County, Colorado)Built 1906; later bypassed by another truss bridgeAbandoned through truss bridge over Arkansas River at Coaldale on CR 6 (Hayden Creek Rd.) just north of US 50Abandoned

Coffee Street Bridge (Fillmore County, Minnesota)Built 1893 by the Chicago Bridge Co.; made obsolete by new bridge on CSAH 8 in 1965; rehabilitated ca. 2002Through truss bridge over Root River on Coffee Street in LanesboroOpen to pedestrians only

Cold Water Creek Bridge (Butler County, Iowa)Built 1905Rumors of this bridge's demise are greatly exageratedOpen to traffic, signed for weight

Coldbrook Bridge (Ulster County, New York)Built 1895; Closed in the 70s; Lost in 2011 post-Irene floodingLost Pratt through truss bridge over Esopus Creek on Nissen Lane in Boiceville, New YorkDestroyed by flooding

Coldwater Bridge (Branch County, Michigan)Built 1920 by the Brookville Bridge Co.Pony truss bridge over Coldwater River on Old US 12 in ColdwaterRemoved but not replaced

Colfax Bridge (Old) (Jasper County, Iowa)Built 1897; Replaced 1922Lost Pratt through truss bridge over Skunk RiverReplaced by a new bridge

College Street Bridge (Warren County, Kentucky)First bridge built 1839. Bridge burned during Civil War in 1862 by Confederate Soldiers. Second bridge built in 1864. Present bridge replaced second bridge in 1915 but original (first bridge) main span pier remains in use to this day.Pratt through truss bridge over Barren River on College StreetOpen to pedestrians

Columbia Bridge (Franklin County, Kansas)Built in 1880 by the Columbia Bridge Works of Dayton, Ohio. Bypassed in 1980, but never removed. Collapsed 2010.Lost Pratt through truss bridge over Marais des Cygnes River on what appears to be a former alignment of Labette Road.Lost

Columbia Bridge (Old) (Philadelphia County, Pennsylvania)Built 1832Lost Pratt through truss bridge over Schuylkill River on RailroadReplaced by a new bridge

Columbus Pike Bridge (Ross County, Ohio)Lost Pratt through truss bridge over Scioto River on Columbus PikeReplaced by a new bridge

Commerce Bridge (Polk County, Iowa)Built 1889; Destroyed 1965Lost Pratt through truss bridge over Raccoon River on Commerce DriveDestroyed by flooding

Commerce Street Bridge (Old) (Dallas County, Texas)Built 1890;Lost Pratt through truss bridge over Trinity River on Commerce StreetReplaced by a new bridge

Compton Junction Bridge (Vernon County, Missouri)Built 1925Through truss bridge over Marmaton River on CR 229 (Old US 71) north of Compton JunctionOpen to traffic

Conboy Bridge (Shelby County, Missouri)Built 1910 by the Pan American Bridge Co. of New Castle, Indiana at a cost of $2795; was named for Thomas Conboy, a local landowner of that period; Had beautiful diagonal lattice work and wooden deck; replaced 2006.Lost through truss bridge over North Fork Salt River on CR 472 beyond the end of Route HHReplaced by a new bridge